Baseline characteristics and follow-up status of the primary Sjogren’s syndrome (pSS) cohort and the age-matched and sex-matched comparison cohort
| Group | Comparison cohort (n=37 872) | pSS cohort (n=9468) | |
| Variable | n (%) | n (%) | p Value* |
| Sex | 1 | ||
| Male | 4836 (12.77) | 1209 (12.77) | |
| Female | 33 036 (87.23) | 8259 (87.23) | |
| Age, mean (SD) | 55.61 (14.33) | 55.64 (14.26) | 0.863 |
| Age groups, years | 0.996 | ||
| ≤50 | 12 945 (34.18) | 3241 (34.23) | |
| 51–65 | 14 643 (38.66) | 3658 (38.64) | |
| >65 | 10 284 (27.15) | 2569 (27.13) | |
| Baseline comorbidity | |||
| Alcoholism | 73 (0.19) | 36 (0.38) | <0.001 |
| Diabetes mellitus | 4327 (11.43) | 1095 (11.57) | 0.702 |
| Gallstone | 423 (1.12) | 272 (2.87) | <0.001 |
| Hepatitis B | 501 (1.32) | 321 (3.39) | <0.001 |
| Hepatitis C | 324 (0.86) | 367 (3.88) | <0.001 |
| Hyperlipidaemia | 4716 (12.45) | 1498 (15.82) | <0.001 |
| Hypertriglyceridaemia | 187 (0.49) | 59 (0.62) | 0.117 |
| No of comorbidities† | <0.001 | ||
| 0 | 30 028 (79.29) | 6674 (70.49) | |
| 1 | 5512 (14.55) | 2108 (22.26) | |
| 2 | 2217 (5.85) | 616 (6.51) | |
| ≥3 | 115 (0.30) | 70 (0.74) | |
| Follow-up duration, mean (SD) | 4.73 (2.78) | 4.64 (2.78) | 0.005 |
| No of acute pancreatitis (AP) | 105 (0.28) | 44 (0.46) | 0.005 |
| AP incidence per 100 000 person-years | 58.56 | 100.05 | 0.004 |
*p values were calculated using the χ2 test for categorical variables or the Student's t-test for continuous variables; the p value for incidence was calculated using the exact Poisson test.
†The number of comorbidity was counted from the predescribed baseline comorbidity, except hypertriglyceridaemia (a subgroup of hyperlipidaemia).